Lobbyists and organizations that seek to influence Washington mostly neglected the presidential campaign of Donald Trump early last year, but by the end of 2016, the sector had begun to embrace him, new lobbying disclosures show.

K Streeters disclosed $5.3 million in donations to Trump — much of that going to the Jan. 20 inauguration — from July through December of last year. That was a huge increase from the 14 donations totaling about $35,000 that lobbyists and their business clients reported during the first six months of last year.

“The campaign saw an uptick in donations, including in Washington post-convention, as the path to victory became clearer for President Trump,” said Dave Tamasi, one of the few lobbyists to back the billionaire businessman’s White House bid early on. “Postelection, it has been a virtual stampede. The realization that long-sought policies could be achieved has only increased donor enthusiasm across the board.”

The biggest donations went to to the inaugural host committee, which offered big donors perks such as entry to special events with Trump, Vice President Mike Pence and Cabinet picks. Donations to inaugural committees are largely unrestricted.

Dow Chemical Co. and pharmaceutical company Pfizer each reported donating $1 million to the inaugural festivities, according to contribution reports that registered federal lobbyists and organizations that employ lobbyists must file semiannually with Congress. A more complete list of donations to the inaugural committee, from nonlobbyists, will be released in the coming weeks.

Altria, Amgen and Exxon Mobil reported donating $500,000 each to the Trump-Pence inaugural committee, while General Motors reported giving $200,000. Insurance company Aetna and energy concern Southern Co. each disclosed $100,000 donations to the committee.

Lobbyists from some of the city’s biggest and best-known firms, including Akin Gump Strauss Hauer & Feld and the BGR Group, also ponied up donations to the Trump campaign and inauguration.

It’s a sharp contrast to K Street’s initial reaction to outsider Trump’s campaign. Lobbyists and their clients reported many more donations to his Democratic opponent, Hillary Clinton, as well as to GOP primary challengers former Florida Gov. Jeb Bush, Florida Sen. Marco Rubio, and Ohio Gov. John Kasich.

On the campaign trail, Trump pledged to “drain the swamp” in Washington and criticized politicians for giving extra access to big campaign donors and lobbyists. He recently signed an executive order limiting future lobbying activities by members of his administration — a ban that ethics watchdogs believe will do little to curb K Street’s influence.

“It’s not rocket science to understand that when somebody becomes president, or is likely to become president, it makes sense to give and then reap the benefits of that giving later on,” said Lisa Gilbert, director of the liberal Public Citizen’s Congress Watch division.

Trump has put corporate America on edge as a president who has taken to Twitter to blast specific companies or entire industries, including pharmaceutical manufacturers. But many of his top priorities line up with what most U.S. businesses say they want, especially rollbacks of financial and environmental regulations and a tax overhaul.

“He’s such an unknown quantity and so unpredictable that giving is just a helpful safety net,” Gilbert added.